YouTube this week cracked down on the videos of some prominent far-right actors and conspiracy theorists, continuing an effort that has become more visible since the school shooting in Parkland, Fla., last month caused a torrent of misinformation to be featured prominently on the site.

A week after the shooting, many of the videos on YouTube’s “Trending” list contained misinformation about the teenage survivors of the shooting. The top video on the list for some time falsely claimed that a student at the school, David Hogg, was a paid actor.

That video and others like it led to intense criticism of the site. Since then, many prominent right-wing personalities have reported that YouTube has issued them strikes, which the site uses to enforce its community guidelines. If a channel receives three strikes within three months, YouTube terminates it.